Hi, Let say you configured endpoint memory in FX2LP to 512 * 4. This way you are allocating 2KB of memory and let say you configured AUTOCONFIG registers with 512. Then as soon as 512 bytes of data has been written into FX2LP FIFO, it will be automatically committed to the USB host. FPGA connected to FX2LP starts writing data into next memory location. Again once 512 bytes are written it will be committed to USB host. This process will continue till 4th 512 bytes block gets filled. Once that is done it will start writing from the 1st one if it is already committed to USB host. There is no buffer switching delay in case of FX2LP. Thanks, sai krishna.